package task;

import java.util.Scanner;

public class Task3_4 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int a = input.nextInt();
        if(isPrime(a)) {
            System.out.println(a + "是一个素数");
        }
        else{
            System.out.println(a + "不是一个素数");
        }
    }
    public static boolean isPrime(int n) {
        boolean s = false;
        int i = 2;
        for (; i <= Math.sqrt(n); i++) {
            if (n % i == 0) {
                s = false;
                break;
            } else {
                s = true;
            }

        }
        if (i > Math.sqrt(n)) {
            return true;
        }
        return s;
    }
}
